There are many systems available to the profession for bonding resin materials to mineralized tooth structures. While enamel bonding is a routine procedure, bonding to dentin is a continuing challenge and a long standing need.
There are many factors that influence the bond strengths of resin materials to dentin. The inherent characteristics of dentin are significantly different than enamel. While the composition of enamel is primarily mineralized tissue, dentin is structurally and chemically different. Acid conditioning of enamel creates a micromechanical retentive surface that produces moderate bond strengths to resin materials. Most current generation adhesive systems use a conditioner or primer on dentin to remove or modify the dentin smear layer in the bonding procedure. The primed or conditioned dentin surface is then typically treated with an adhesive resin to provide a bonding interface between the dentin and a resin restorative material. The adhesive bonding interface between dentin and a composite resin material is generally considered the weak link in the system.
There are many factors that influence the bond strength of adhesive resin materials to dentin. Generally, adhesive resins are applied in a thin layer. An object of this invention is to provide a device capable of improving the bond strengths of dentin and enamel to composite materials. A further object is to provide an apparatus capable of providing an inert gas blanket over the work area of an actinic light curable adhesive composite repair of dentin or enamel tooth surface. An advantage of the apparatus of this invention is that it can suppress oxygen inhibition of the actinic light curable adhesive and composite systems. A further advantage is that the apparatus of the invention essentially eliminates atmospheric oxygen on the surface during visible light polymerization of photocurable resin systems.